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CHRISTINE BUCHEL, MD, of Winnipeg, MB, writes, "A 19-year-old woman was recently diagnosed with iron- deficiency anemia, with a hemoglobin of 103 g/L, microcytic hypochromic cellular indices, and a ferritin of 3 ug/L. White blood cell counts and platelets are normal, and stool for occult blood is negative. She has adequate iron intake but suffers from moderate to heavy menstrual blood loss. She's asymptomatic apart from mild fatigue." She asks, "What further workup is warranted at this time? Can this degree of iron deficiency be attributed to menstrual losses alone?"

In North America, by far the most common cause of iron-deficiency anemia in such patients is menstrual blood loss. The main reason for full investigation of adults with iron deficiency is to make sure that they don't have a gastrointestinal malignancy -- which is extremely rare in 19-year-old women. Moderate to heavy blood loss would easily explain the iron deficiency of this patient, especially considering that stool for occult blood loss is also negative, so no other investigation is needed. MS